1) Field of the Invention
The present invention relates generally to pull-type agricultural implements and, more specifically, to a hitch for such implements.
2) Related Art
Conventional hitch and hitch link structures presently used on drawn implements such as chisel plows, field cultivators and seeding equipment include numerous parts and require extensive welding. As a result, these structures are relatively expensive to manufacture and are more prone to reliability problems. Further, different implements require different hitch frame angles and therefore different parts. Different implement main frame widths on one type of implement require hitch structures of different dimension. The various fixturing and part requirements for the varying hitch structures increase the number of parts as well as the cost and complexity of the manufacturing process.
Hitch structures also include safety chain mounting structure. Safety chains are usually attached using a separate set of bolts and a separate plate for intermediate support, thereby further increasing the time and number of necessary parts for the manufacture of the hitch structure.
It is therefore an object of the present invention to provide an improved hitch link structure. It is a further object to provide such an improved structure that overcomes most or all of the aforementioned problems.
It is a further object of the present invention to provide an improved hitch link structure that is simpler and less expensive to manufacture than at least most previously available hitch link structures. It is a further object to provide such a hitch link structure that requires a minimum number of parts and which is higher in quality than at least most of the previous structures.
It is still another object of the present invention to provide an improved hitch link structure wherein common components can be used for a variety of different hitch tube angles and sizes. It is yet another object to provide such a structure which accommodates a safety chain without need for additional components.
It is yet another object of the present invention to provide an improved hitch link structure including plates for receiving different hitch links, the plates including apertures utilized to connect a link and which facilitate fixturing for hitch manufacture. It is a further object to provide such structure wherein one of the plates includes a safety chain intermediate support hole and one of the bolts connecting the hitch link to the plates attaches the safety chain to the hitch.
A hitch link structure constructed in accordance with the teachings of the present invention includes two hitch tubes angled with respect to each other and having forward ends connected by upper and lower hitch plates welded to the tubes. The plates include weld cutouts designed so the same plates can be used with a variety of different hitch tube angles, depending on the width of the mainframe hitch mount-up. Three apertures in the forward end of each of the plates receive bolts which connect the selected hitch link, clevis or standard to the plates. The apertures also act as weld fixturing locators to speed hitch construction. The weld cutouts, in generally a U-shaped configuration with a rounded inner portion and parallel sidelegs embracing the sidewalls of the tubes, facilitate low cost fillet welds at easily accessible and relatively lowly stressed locations along the sidelegs, outside the tube, regardless of hitch tube angle.
The lower plate is apertured to define an intermediate support hole for the safety chain, and the central bolt connecting the hitch link also attaches to the safety chain so the chain is accommodated without additional parts. The hitch construction is simpler yet stronger and more reliable than most previously available constructions. In addition, the components are adaptable to different hitch angles so the number of parts required for different families of different hitch types is substantially reduced.
In a second embodiment of the invention, a single hitch tube includes a forward end with opposed sets of walls, and a pair of plates are notched and received over one set of the walls. Welds adjacent the notched areas connect the plates with the walls at easily accessible locations. The hitch link and chain are connected in a manner similar to that described above for the hitch which includes two angled tubes, and the single tube structure has many of the same advantages outlined above.
These and other objects, features and advantages of the present invention will become apparent to one skilled in the art upon reading the following detailed description in view of the drawings.